Did you ever wonder what the difference between DVD-R and DVD+R is? Each time I was buying blank DVDs I wondered… and then ignored it. Both standards are equally expensive and my DVD writer can write both.

Copy protection ring

This week, I had to write a DVD for a project delivery. I opened a fresh pack of blank DVDs and examined them a bit closer than usual. I noticed a strange ring on the data layer. At first I thought of a fault in the material and was quite frustrated with the thought of trashing all those DVDs.

Then I decided to ask the Internet first – and found out I was wrong. This strange ring is a copy protection. It is a small area where the encryption keys of video DVDs are stored. On DVD-Rs, this area is pre-recorded, so you can’t copy this key.

It’s not a bug, it’s a feature.

Identification code and higher production costs

There is no such limitation on DVD+Rs. DVD+R writers also do not write an unique identification code on the DVDs, like DVD-R writers do.

Producing DVD-Rs is also more expensive than producing DVD+Rs. The copy protection ring and another unique identification number have to be written on each DVD. This takes more time and therefore results in higher costs. Additionally, DVD-R producers have to pay more license fees to the DVD-Forum.

There are no real big disadvantages for DVD+Rs. DVD+R is not supported by the official DVD-Forum, so these DVDs are not allowed to carry the official DVD logo. Since this great DVD-Forum is also responsible for the limitations on DVD-Rs, the infamous region codes and CSS copy protection on video DVDs, this does not appear to be much of a loss. It’s also not a problem for compatibility – both types are about equally compatible to standalone players.

To make it short: DVD-R is evil and has only disadvantages compared to DVD+R.

Update 26.8.2006

Commenters here and at reddit.com said that DVD+R are less compatible to standalone players. According to the German c’t magazine, the difference is marginal:

At the last test, 93 percent of the DVD players worked with DVD+R. That’s 2 percent less than with DVD-R. Using a ‘compatibility tool’ to change the bit for media identification to DVD-ROM, both formats were equally recognized by 95 percent of the players.

(translation by me)

Update 26.8.2006, II

Sorry for posting yet another update, but I feel I need to clarify something: Many postings that refer to me indicate that I propose DVD+R because you can copy original video DVDs with it. That is not the case.

In fact, most DVDs are simply too big to copy on a single layer DVD anyway. It is also very likely that there are additional copy protection mechanisms in the firmware of your DVD writer, so that it’ll refuse to copy DVDs on DVD+R even though it would be physically possible. (Haven’t tried, yet. If anyone did, please leave a comment)

My point is more an idealistic one: The DVD-R has intentionally been limited in its capabilities just to make the movie industry happy. Not only was this little successful – we all know how easy it is to completely strip the copy protection off a DVD – it also made the process of producing them more complicated. Additionally, those identification codes are yet another unnecessary privacy invasion.

That is why I think that DVD-Rs are morally inferior to DVD+R. In practice, the difference isn’t that big.

Unfortunately DVD-R came first and that’s where all DVD players started. Compatibility was added later for DVD+R but the design was meant to work with DVD-Rs. It has been observed that in older DVD playing devices (such as the Playstation 2), DVD-Rs do perform better than DVD+Rs from read speed to compatibility.

My own anecdotal evidence is that my PS2 when reading a DVD+R disc whines like a dremel and doesn’t when playing a DVD-R disc.

I’m under the impression that DVD-R’s tend to be more compatible with the wide range of (standalone, not computer) DVD players out there. So while I agree with your sentiments about the problems with DVD-R, the choice is not always so clear.

The consumer DVD players in my house all play my DVD-R recorded video, but not all play DVD+R. Therefore, whether or not DVD-R is evil, to me it has the most important advantage over DVD+R – playability.

Originally there was only one recordable DVD format (now called “authoring”). Its intended use was DVD authoring and it was quite expensive partly due to the requirement for a different write laser. When a consumer recordable format was inevitable, Pioneer developed a new DVD-R format that used a different dye to eliminate the need for a second laser, but they had to protect the investment in the old standard by disabling the ability to author DVDs. That’s what the “ring” referenced is. It is of no special consequence to home users and the claim that it somehow makes DVD-R evil is absurd. Anyone who wishes to copy DVDs removes copy protection anyway and has no need for the disabled area.

As far as production costs go, what does it matter? All that matters is how much you pay. For a very long time, DVD-R was substantially less expensive by virtue of its headstart in the market.

craig, thanks for the history insight. It doesn’t affect my point, though. DVD-R is still arbitrarily limited.

You might argue about my choice of words (“evil” was not meant in any religious sense), but I still think that artificially limiting a format isn’t exactly friendly towards the customers.

Besides, only caring about the price in the store is a little short-sighted. This teaches the industry that they can cripple products as long as they are still cheap enough… and has some more problematic implications with other products (child labor, for example).

Look I asked about that +-r thing too-
someone at office depot told me +rs burn and
read from the inside-out,and -rs from the outside-in.I thought that was the only difference.by the way all discs need some
kind of info on them so that dvd drives
can I.D. them.

Hey thanks for the info…I just bought a stack of Memorex DVD-R but took them back cuz the copyright protection, then got some Compusa DVD-R and now have to take them back too. I compared the -R to the +R and noticed the RING. But thanks cuz I was worried I couldn’t burn movies anymore.